Forget having to replace their sleeping bag every season when you pick up the height-adjustable design of the Big Agnes Kids' Duster Sleeping Bag. This 15-degree synthetic bag features external hook-and-loop fasteners for adjusting its overall length, meaning they'll be able to use this bag through multiple camping seasons, even when they're growing rapidly in those adolescent years. Because it's height-adjustable, the Duster Sleeping Bag keeps insulation close to their body, thereby eliminating the potential cold spots they'd experience while sleeping in a longer adult-sized bag. Besides its ingenious size adjustments, the Duster Sleeping Bag is a reliable option for shivery nights at high elevations and freezing evenings in cold climates with its 15-degree rating. It's generously filled with M4 synthetic insulation, which provides the heat-trapping loft required for camping out in colder environments. Another benefit, it's not as susceptible to outside moisture and condensation as its down counterparts, meaning they'll stay warmer in the wet and damp.